This invention relates generally to the field of sockets for electronic components and devices. More particularly, it relates to a socket for integrated circuit devices, especially those of the so-called "small outline" type, in which the device can be installed or "socketed" with little or no insertion force applied to the body of the device, and with subsequent retention forces applied substantially only to the leads of the device.
The use of integrated circuit ("IC") devices has become commonplace in the electronics field. One type of IC device which has recently gained popularity is the "small outline" or "SO" device. The SO device resembles the standard dual-in-line package ("DIP") device, but it is substantially smaller in size, with short, stubby pins with horizontal end tabs, as opposed to the long, thin, generally vertical pins of the standard DIP device.
In many applications, the IC device is "surface-mounted", that is, soldered or otherwise permanently fastened directly onto a circuit board. In some applications, however, a permanent installation is not desired, due to a need, for example, to remove the device periodically. This is true, for example, in testing and "burn-in" procedures. In such applications, a socket is necessary for the temporary installation of an IC device into a testing or burn-in circuit.
Small outline devices pose particular socketing problems because of their small size. For example, the pin configuration of the SO device is not suitable for standard DIP sockets, and maintaining good electrical contact between SO device pins and socket contacts is difficult. Compounding this problem is the relatively delicate nature of SO devices, which mandates the use of sockets that require relatively little force on the body of the device to insert the device into, and remove it from, the socket.
Accordingly, specialized sockets have been devised specifically for use with SO devices. An example is disclosed in U.S. Pat. No. 4,461,525 to Griffin. The Griffin device employs hinged "clamp wings" mounted on the sides of the socket. Each clamp wing includes conductive leads having terminal contacts which make contact with the SO device pins when the clamp wings are pivoted into their upright position. With this arrangement, the clamp wings provide electrical contact with the SO device pins, while also retaining the device within the socket.
The Griffin device has the desirable characteristic of low insertion force. Nevertheless, the need to combine the low insertion force feature with good physical retention, simplicity of design, and durability of electrical contact integrity has led to a search for further improvements in the design of SO device sockets.